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//go:build stm32 && !stm32f103
package machine
import (
"device/stm32"
)
// GPIO for the stm32 families except the stm32f1xx which uses a simpler but
// less flexible mechanism. Extend the go:build directive above to exclude other
// models in the stm32f1xx series as necessary
const (
// Mode Flag
PinOutput PinMode = 0
PinInput PinMode = PinInputFloating
PinInputFloating PinMode = 1
PinInputPulldown PinMode = 2
PinInputPullup PinMode = 3
// for UART
PinModeUARTTX PinMode = 4
PinModeUARTRX PinMode = 5
// for I2C
PinModeI2CSCL PinMode = 6
PinModeI2CSDA PinMode = 7
// for SPI
PinModeSPICLK PinMode = 8
PinModeSPISDO PinMode = 9
PinModeSPISDI PinMode = 10
// for analog/ADC
PinInputAnalog PinMode = 11
// for PWM
PinModePWMOutput PinMode = 12
)
// Define several bitfields that have different names across chip families but
// essentially have the same meaning.
const (
// MODER bitfields.
gpioModeInput = 0
gpioModeOutput = 1
gpioModeAlternate = 2
gpioModeAnalog = 3
gpioModeMask = 0x3
// PUPDR bitfields.
gpioPullFloating = 0
gpioPullUp = 1
gpioPullDown = 2
gpioPullMask = 0x3
// OSPEED bitfields.
gpioOutputSpeedVeryHigh = 3
gpioOutputSpeedHigh = 2
gpioOutputSpeedMedium = 1
gpioOutputSpeedLow = 0
gpioOutputSpeedMask = 0x3
)
// Configure this pin with the given configuration
func (p Pin) Configure(config PinConfig) {
// Use the default system alternate function; this
// will only be used if you try to call this with
// one of the peripheral modes instead of vanilla GPIO.
p.ConfigureAltFunc(config, 0)
}
// Configure this pin with the given configuration including alternate
//
// function mapping if necessary.
func (p Pin) ConfigureAltFunc(config PinConfig, altFunc uint8) {
// Configure the GPIO pin.
p.enableClock()
port := p.getPort()
pos := (uint8(p) % 16) * 2 // assume each field is two bits in size (with mask 0x3)
switch config.Mode {
// GPIO
case PinInputFloating:
port.MODER.ReplaceBits(gpioModeInput, gpioModeMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
case PinInputPulldown:
port.MODER.ReplaceBits(gpioModeInput, gpioModeMask, pos)
port.PUPDR.ReplaceBits(gpioPullDown, gpioPullMask, pos)
case PinInputPullup:
port.MODER.ReplaceBits(gpioModeInput, gpioModeMask, pos)
port.PUPDR.ReplaceBits(gpioPullUp, gpioPullMask, pos)
case PinOutput:
port.MODER.ReplaceBits(gpioModeOutput, gpioModeMask, pos)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
// UART
case PinModeUARTTX:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullUp, gpioPullMask, pos)
p.SetAltFunc(altFunc)
case PinModeUARTRX:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
p.SetAltFunc(altFunc)
// I2C
case PinModeI2CSCL:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OTYPER.ReplaceBits(stm32.GPIO_OTYPER_OT0_OpenDrain, stm32.GPIO_OTYPER_OT0_Msk, pos/2)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullUp, gpioPullMask, pos)
p.SetAltFunc(altFunc)
case PinModeI2CSDA:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OTYPER.ReplaceBits(stm32.GPIO_OTYPER_OT0_OpenDrain, stm32.GPIO_OTYPER_OT0_Msk, pos/2)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullUp, gpioPullMask, pos)
p.SetAltFunc(altFunc)
// SPI
case PinModeSPICLK:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
p.SetAltFunc(altFunc)
case PinModeSPISDO:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
p.SetAltFunc(altFunc)
case PinModeSPISDI:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedLow, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
p.SetAltFunc(altFunc)
// PWM
case PinModePWMOutput:
port.MODER.ReplaceBits(gpioModeAlternate, gpioModeMask, pos)
port.OSPEEDR.ReplaceBits(gpioOutputSpeedHigh, gpioOutputSpeedMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
p.SetAltFunc(altFunc)
// ADC
case PinInputAnalog:
port.MODER.ReplaceBits(gpioModeAnalog, gpioModeMask, pos)
port.PUPDR.ReplaceBits(gpioPullFloating, gpioPullMask, pos)
}
}
// SetAltFunc maps the given alternative function to the I/O pin
func (p Pin) SetAltFunc(af uint8) {
port := p.getPort()
pin := uint8(p) % 16
pos := (pin % 8) * 4
if pin < 8 {
port.AFRL.ReplaceBits(uint32(af), 0xf, pos)
} else {
port.AFRH.ReplaceBits(uint32(af), 0xf, pos)
}
}
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